His heart was visible, and the dismal sack that maketh excrement of what is eaten.

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Posted On:8/27/2012 9:25am

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Originally Posted by mike321

Sorry, not trying to move goal posts, lots of speculating on my part and just started researching this. Obviously the technology already affects how AR 15 enforcement (the law remains the same) because they have a working receiver design already for 3d printers.

I am not convinced the material science issues of making a barrel won't be overcome. Just have to wait and see.

As for using a barrel from a different weapon I do think you are right about the obstacles. However, the 3d printer may allow some sort of conversion kit or selling barrels without the rest of the weapon. (I know moving goal post again, but this is mostly speculating as I post)

I'm not clear on your point about the AR15 design. They may have a design for an AR15 receiver but they can only cut it out of plastic. Stepping that up to aluminum and steel would require a whole new set of machinery and tooling. Personally, I don't think there is a law enforcement issue here. It's a self correcting problem. A couple hundred rounds of hot gas slamming into your plastic gas key on your plastic bolt carrier and the illegal gun will go bye-bye, probably taking the offender with it.

As for material sciences and barrels - don't underestimate what it takes to make a barrel and don't underestimate the forces a barrel is subjected to. Average chamber pressure is going to run around 55,000 psi, give or take. Making a rifled barrel is an extremely difficult undertaking requiring equipment that is massive and outrageously expensive. Most of the finest gun builders in the world buy barrels instead of making them for this very reason.

The idea that a bunch of average people will be making steel rifled barrels at home is out of the question. The only way this would ever be possible would be if some tiny machinery with futuristic technology was developed - like maybe some type of laser cutter with light saber grade lasers or some ****. We're a long, long way from that at this point.

As for the possibility of using some alternative material for manufacturing barrels, I'll put this in the never say never category. But think about this. If it's strong enough to withstand the heat and pressure it's going to have to be just as rock solid as hardened steel, which will mean it's going to be equally difficult to work with.

I believe in technology and I know we can't predict what the future will bring. But if you ignore the obstacles you're just dealing in fantasy.

I think the technology in the OP's link is good technology. I think it could change people's lives. But I think they chose a shitty example to showcase their project. A gun is not the right way to go. Their plastic gun will be a dangerous, shoddy piece of junk and of no real use to anyone. If they had chosen to make tools or something more simple and practical they'd get their point across better IMO.

Here is some info on the AR 15 lower from a printer. He starts with a 22lr then 223. Other articles are out there but they tend to have too much hype.

Where's his homemade bolt? There isn't one because he used a steel bolt and bolt carrier.

What he did was cool but it only has merit for someone who wants to save a couple hundred bucks by making a stripped lower instead of buying it. It's useless without the proper steel parts to go along with it. If you've got the other 80% of the parts to build an AR, you can probably get your hands on a stripped lower too. Not quite the everyman's future weapon there.

Regardless of whether or not the printer can produce a good gun, I think its a great illustration of concept for one to print a gun that can even fire a few bullets. That's quite a mechanical feat for a small multipurpose manufacturing machine.

One could probably print a functioning receiver for a thompson center single shot. I'm sure it would be ok for 22lr barrel. Altho it would only be a matter of time untill some genius tried a larger cartridge and destroys his face. I think you may be able to pull of a 10/22 receiver and bolt. Maybe?

His heart was visible, and the dismal sack that maketh excrement of what is eaten.

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Posted On:8/27/2012 12:17pm

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Originally Posted by Permalost

Regardless of whether or not the printer can produce a good gun, I think its a great illustration of concept for one to print a gun that can even fire a few bullets. That's quite a mechanical feat for a small multipurpose manufacturing machine.

I agree. It's cool. But that's where it ends. It has no practical value and the guys writing the program are describing it as the future of freedom and an end to gun control. It is neither of those things and advances in software or printing technology are not going to change that fact.

Checking out some of the technology. I am pretty sure they will be able to print high strength metal parts but these will not be low cost do it at home printers. The plastic printers will be limited until a material science break through happens. Right now the plastic is two orders of magnitude lower tensile strength than plastic. (not even looking at other important properties). Guessing that one order of magnitude could be handled with design mods, not two. Short version you are right about this being gimmicky.